1. Field of the Invention
The present invention relates to electrical connector assemblies such as those used to connect portions of electrical utilities below-ground and more particularly to loadbreak separable connectors.
2. Description of the Related Art
High-voltage separable connectors interconnect sources of energy such as transformers to distribution networks or the like. Frequently, it is necessary to connect and disconnect the electrical connectors. These connectors typically feature an elbow component, which contains a male connector, and a bushing component, which contains a female connector. When the components are connected, elastomeric O-tings seal the connection.
Disconnecting energized connectors is an operation known as a loadbreak. A problem known as "flashover" has been known to occur while switching or separating loadbreak separable connectors. The male connector probe is typically maintained within the elbow, and the female connector contact is contained within the bushing. During a loadbreak operation, the elbow is pulled from the bushing using a hotstick to separate the components. This, in effect, creates an open circuit. During separation, a phenomenon known as a flashover may occur where an arc from the energized connector extends rapidly to a nearby ground. Existing connector designs contain a number of arc extinguishing components so that the devices can have loadbreak operations performed under energized conditions with no flashover to ground occurring. The object of caution is to control the arc and gases generated during loadmake and loadbreak operations. Even with these precautions, however, flashovers have occurred on rare occasions. In a flashover, an arc extends from an energized portion of one of the connectors and seeks a nearby ground. Flashovers commonly occur during the initial approximate one-inch of separation of the connectors from each other. The separation of the elbow from the bushing causes a partial vacuum to surround the energized components of the connector assembly. Because a partial vacuum presents a lower dielectric strength than that of air at atmospheric pressure, a flashover is more likely to occur at the moment as the elastomeric seal between the components is broken and before atmospheric pressure is reestablished around the energized portions of the components. Also, after being connected over a long period of time, the elbow may adhere to the bushing interface so that the connectors cannot be easily disengaged. This is known as a stuck condition, and greater force is required to separate the elbow resulting in a more rapid change in pressure and dielectric strength in the air surrounding the energized components.
During a flashover, an electrical arc between the energized components and ground may result which could cause damage to the equipment and possibly create a power outage. The problem of flashovers involves principally 25 KV and 35 KV loadbreak connectors but may also include 15 KV connectors.